1. Field of the Invention
The invention relates to a device for driving the movable portion of a printer by means of a tape which is secured to a drum so as to be capable of being wound around the drum and unwound from it. In such a printer the drum is driven by a rotating motor in one direction or in the other.
2. Description of the Prior Art
In known drives of the type described the tape is wound around one drum and unwound from the other drum with the turns lying on each other, and the tape is led to the movable portion over guide rollers. Because the effective length of the flexible tape, which generally is made of steel, is not constant owing to the oppositely varying effective diameters of the take-up and take-off drums, at least one of the guide rollers must be pivotally mounted to obtain a resilient arrangement. In addition, positioning the portion to be moved, for example the carriage, of the printer requires a complicated and expensive control device owing to the aforementioned varying effective length.